$5.$ Shoppers on Amazon.com have differing needs that must be satisfied during the exchange which often include the need for information, convenience, variety, and$/$or pre$-$ or postsale services. These needs are collectively referred to as $\_\_\_\_\_\_\_\_\_\_\_.$

A$)$ seller requirements B$)$ exchange parameters C$)$ dual distribution D$)$ buyer requirements E$)$ distribution intensity